Regulating combustion in furnaces



F. H. BROWN.

REGULATING COMBUSTION IN FURNACES.

APPLICATION FILED FEB. 12, 1920.

1,338,901 Patented May 4, 1920.

fiwelllor 3 W H HQMW g W H. BBU'WN, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO JOHN M.

HQP'WOOD, OF PITTSBURGH, PENNSYLVANIA.

REGULATING COMBUSTION IN FURNACES.

flubstitute for application Serial No. 184,261, filed August 3, 1917.

Specification 01' Letters Patent.

1920. Serial No. 358,108.

To all whom it may concern Be it known that I, FRANCIS H. BROWN residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, a citizen of the United States,.have invented or discovered certain new and useful Imrovements in Regulating Combustion in l urnaces, of which improvements the following is a specification.

The invention described herein consists, generally stated, in controlling the flow of products of combustion from a fire box or furnace of a boiler by. and in accordance with the flow of steam from the boiler and controlling the feed of fuel and the flow of air to maintain combustion by and in accordance with the changes of pressure 1n the fire box or furnace, resulting from the controlled escape of the products of combustion from the furnace.

The invention also consists in controlling the flow of feed water to the boiler by and in accordance with the rate of flow of steam from the boiler. The invention is hereinafter more fully described and claimed.

In the accompan ing drawing formmg a part of this speci cation, is shown a diagrammatic view of a boiler and its setting and having applied thereto apparatus and appliances suitable for the practice of the invention.

It will be understood that the method hereinafter described may be practised with any type or constructionof boiler and furnace, and that although the apparatus and appliances shown and described herein are well adapted to the practice of the method, any other suitable construction may be emplo ed.

n the practice of the invention, suitable means are employed whereby the difference between the static pressure of steam flowing from the boiler and the static pressure plus the pressure due to the velocity of flow of the steam, or minus the drop of pressure due to the flow of steam through an orifice less than the diameter of the steam pipe, is utilized for producing motion which in turn is utilized for regulating the pressure of gases in the fire box or furnace. Suitable means for effecting these objects consist of a Pitot tube 1 arranged in the steam pipe 2 leading to the engine 3. The nozzles 4: and

5 of this tube are connectedby pipes 6 and T on opposite sides of the diaphragm of a diaphragm motor 9. This diaphragm is adjustably connected by an arm 10 to a pivotally mounted frame 11 and on the frame is pivotally mounted a bell crank lever 12 having an arm connected to the movable member of a valve mechanism 13, of any su1table construction, and the other arm connected by a rod 14 to a pivotally mounted standard 15. A shoe, pivotally con nected to the standard so engages an angle rod 12, carried by the frame 18, as to permit of the angular adjustment of the rod. The frame 18 is secured to a rod 19 connected by an arm 20 to the piston rod of a fluid pressure cylinder 21. This compensating motor mechanism is more fully described and shown in application filedof even date herewith, Serial No. 358,107.

In the operation of this mechanism, a movement of the diaphragm of motor 9 will shift the frame 11 and the movable member of the valve mechanism 13 connected to said frame, so as to permit of the flow of fluid under pressure through one of the pipes 22 or 23 to the end of the cylinder 21 and the escape of fluid from the opposite end of the cylinder. As the piston of the cylinder is moved, the angle rod 17 will be shifted and by reason of its inclination will rock the standard 15. As the latter is connected to the bell crank lever 12, the latter will be shifted and thereby move the movable member of the valve mechanism 13 in a direction opposite that imparted by the movement of the frame 11, thereby cutting oil the flow of fluid under pressure to and from the cylinder 21.

The piston rod 25 of the cylinder 21 is connected by any suitable means to the damper 26 in the conduit through which products of combustion flow from the fire box or furnace 27 to a stack. In the construction shown, a cord or chain 28 is connected to the rod 25 and passing around a suitable guide pulley, is wound two or more times around the drum 29 on the shaft of the damper 26 and is connected to a counter balancing weight.

In case of an increase in the rate of flow of steam through the pipe 2, the mechanism hereinbefore described will be so operated as or increase the pressure within the fire box and by means of suitable appliances the variations in pressure will cause a proportional but reverse adjustment in the flow of air through the bed of fuel, e., an increase of pressure in the fire box will be followed by a reduction in the feed of air and a reduction of pressure in the fire box will bring about an increase in the quantity of airsupplied.

A convenient means for controlling the feed of air to the fire box as shown and described in Letters Patent No. 1,150,097, dated August 17, 1915, and diagrammatically shown in A herein.

In the operation of the pressure actuated mechanism A, due to changes of pressure in the fire box, fluid is admitted to one or the other end of a cylinder 31, thereby causing an up and down movement of the piston rod 32. This rod is connected to one end of a flexible cord or chain 33 passing around guide pulleys 34 and two or more times around a drum 35 on the shaft of the damper 36 arranged in the conduit 37 extending from the uniformly operating blower 38 to the ash pit of the fire box. In the arrangement shown, the damper is moved in one direction by a pull exerted on the operation of the pressure actuated mechanism and in the opposite direction by a weight 39, the

operation of the pressure actuated mechanism being reversed. While the construction and combination of appliances herein shown and described are well adapted for feeding fuel and controlling the feed of air to the ash pit, the invention claimed herein is not limited to such specific constructions and combinations, as other means for supplying air and fuel as re uired by changes of pressure conditions in t e fire box, due to changing in the rate of flow of steam from the boiler, will readily suggest themselves to those skilled in the art.

The supply of fuel is also controlled by changes of pressure in the fire chamber putting into operation the pressure actuated mechanism A. As shown, the lower end of the-piston rod 32 is connected by a lever 43 to the rod 44 of the movable member of the valve mechanism 45, which is connected by a pipe 46 to the boiler or other suitable source of fluid under pressure, and by the pipe 4'? to the motor of a stoking mechanism 48 which may be of any suitable type or construction. Connection of the piston rod 32 to the valve mechanism 45 is so arranged that the movement of the rod 32 to permit of the admission of a greater flow of air to the ash pit will so shift the movable member of the valve mechanism 45 as will result in an acceleration of the stoking mechanism and an increased feed of fuel to the fire box.

As hereinbefore described, provision is made for controlling combustion in accordance with the steam requirements, combustion increasing or decreasing by changing the supply of fuel, and air for combustion as the demand for steam varies. Changes in the rate of flow of steam not only necessitates changes in combustion but also an adjustment of the feed of water to the boiler, and to attain the best results, the feed of water should be proportional to the consumption of steam. To this end, the piston rod 25 of the cylinder 21 is connected to a valve 49 in the feed water pipe 50. A suit able connection consists in a cord or chain 41 having one end connected to the cord or chain 33 and its opposite end to an arm of the valve 49. The valve may be shifted in a direction opposite that imparted by thepiston in cylinder 21 by a weight 42.

It will be obvious to those skilled in the art that the pressure actuated device can be connected to means employed and well known in the art for regulating the flow of liquid or gaseous fuel to the furnace and also for the air necessary for the proper combustion of such fuel.

This application is filed in place of application Serial No. 184,261, filed August 3, 1917, but became abandoned February 23, 1919.

I claim herein as my invention:

1. The, method herein described of con trolling combustion in furnaces of boilers which consists in changing the rate of discharge of gases from the furnace by and in accordance with the flow of steam from the boiler, and regulating the feed of fuel and the flow of air into the furnace by and in accordance with variations of pressure in the furnace.

2. The method herein described which consists in changing the rate of discharge of gases from the furnace of a boiler and the feed of water to the boiler by and in accordance with the flow of steam from the boiler accordance with the changes of pressure in the furnace.

4. The method herein described which consists in changing the rate of discharge of gases from the furnace of a boiler and feed of Water to the boiler, byand in accordance with the rate of flow of steam from the boiler and regulating the feed of fuel and the supply of air for combustion in accordance with changes of pressure in the furnace. 10

In testimony whereof I have hereunto set my hand.

FRANCIS H. BROWN. 

